/*
 * Copyright (c) 2003-2013, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.log.window.impl;

import java.awt.event.InputEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Arrays;
import java.util.Date;
import java.util.Vector;

import javax.swing.JTable;
import javax.swing.event.TableModelEvent;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableColumnModel;
import javax.swing.table.TableModel;

import org.knopflerfish.bundle.desktop.swing.Activator;

public class TableSorter extends TableMap {
    private static final long serialVersionUID = 1L;

    int             indexes[];
    Vector<Integer>          sortingColumns = new Vector<Integer>();
    boolean         ascending = true;
    int compares;

    public TableSorter() {
        indexes = new int[0]; // for consistency
    }

    public TableSorter(TableModel model) {
        setModel(model);
    }

    @Override
    public void setModel(TableModel model) {
        super.setModel(model);
        reallocateIndexes();
    }

    public int compareRowsByColumn(int row1, int row2, int column) {
        final Class<?> type = model.getColumnClass(column);
        final TableModel data = model;

        // Check for nulls.

        final Object o1 = data.getValueAt(row1, column);
        final Object o2 = data.getValueAt(row2, column);

        // If both values are null, return 0.
        if (o1 == null && o2 == null) {
            return 0;
        } else if (o1 == null) { // Define null less than everything.
            return -1;
        } else if (o2 == null) {
            return 1;
        }

        /*
         * We copy all returned values from the getValue call in case
         * an optimized model is reusing one object to return many
         * values.  The Number subclasses in the JDK are immutable and
         * so will not be used in this way but other subclasses of
         * Number might want to do this to save space and avoid
         * unnecessary heap allocation.
         */

        if (type.getSuperclass() == java.lang.Number.class) {
            final Number n1 = (Number)data.getValueAt(row1, column);
            final double d1 = n1.doubleValue();
            final Number n2 = (Number)data.getValueAt(row2, column);
            final double d2 = n2.doubleValue();

            if (d1 < d2) {
                return -1;
            } else if (d1 > d2) {
                return 1;
            } else {
                return 0;
            }
        } else if (type == java.lang.Integer.class) {
	  final int d1 = ((Integer)data.getValueAt(row1, column)).intValue();
	  final int d2 = ((Integer)data.getValueAt(row2, column)).intValue();

	  if (d1 < d2) {
	    return -1;
	  } else if (d1 > d2) {
	    return 1;
	  } else {
	    return 0;
	  }
        } else if (type == java.util.Date.class) {
            final Date d1 = (Date)data.getValueAt(row1, column);
            final long n1 = d1.getTime();
            final Date d2 = (Date)data.getValueAt(row2, column);
            final long n2 = d2.getTime();

            if (n1 < n2) {
                return -1;
            } else if (n1 > n2) {
                return 1;
            } else {
                return 0;
            }
        } else if (type == String.class) {
            final String s1 = (String)data.getValueAt(row1, column);
            final String s2    = (String)data.getValueAt(row2, column);
            final int result = s1.compareTo(s2);

            if (result < 0) {
                return -1;
            } else if (result > 0) {
                return 1;
            } else {
                return 0;
            }
        } else if (type == Boolean.class) {
            final Boolean bool1 = (Boolean)data.getValueAt(row1, column);
            final boolean b1 = bool1.booleanValue();
            final Boolean bool2 = (Boolean)data.getValueAt(row2, column);
            final boolean b2 = bool2.booleanValue();

            if (b1 == b2) {
                return 0;
            } else if (b1) { // Define false < true
                return 1;
            } else {
                return -1;
            }
        } else {
            final Object v1 = data.getValueAt(row1, column);
            final String s1 = v1.toString();
            final Object v2 = data.getValueAt(row2, column);
            final String s2 = v2.toString();
            final int result = s1.compareTo(s2);

            if (result < 0) {
                return -1;
            } else if (result > 0) {
                return 1;
            } else {
        	return 0;
            }
        }
    }

    public int compare(int row1, int row2) {
        compares++;
        for (int level = 0; level < sortingColumns.size(); level++) {
            final Integer column = sortingColumns.elementAt(level);
            final int result = compareRowsByColumn(row1, row2, column.intValue());
            if (result != 0) {
                return ascending ? result : -result;
            }
        }
        return 0;
    }

    public void reallocateIndexes() {
        final int rowCount = model.getRowCount();

        // Set up a new array of indexes with the right number of elements
        // for the new data model.
        indexes = new int[rowCount];

        // Initialise with the identity mapping.
        for (int row = 0; row < rowCount; row++) {
            indexes[row] = row;
        }
    }

    @Override
    public void tableChanged(TableModelEvent e) {
        //System.out.println("Sorter: tableChanged");
        reallocateIndexes();

        super.tableChanged(e);
    }

    public void checkModel()
    {
      if (indexes.length != model.getRowCount()) {
        try {
          throw new Exception("Sorter not informed of a change in model.");
        } catch (final Exception e) {
          final String msg = "indexes.length = " + indexes.length +", model.getRowCount() = " + model.getRowCount()
              + ", indexes: " +Arrays.asList(indexes) +", model. " +model.toString();
          Activator.log.error(e.getMessage() + "; " +msg, e);
        }
      }
    }

    public void sort(Object sender) {
        checkModel();

        compares = 0;
        // n2sort();
        // qsort(0, indexes.length-1);
        shuttlesort(indexes.clone(), indexes, 0, indexes.length);
        //System.out.println("Compares: "+compares);
    }

    public void n2sort() {
        for (int i = 0; i < getRowCount(); i++) {
            for (int j = i+1; j < getRowCount(); j++) {
                if (compare(indexes[i], indexes[j]) == -1) {
                    swap(i, j);
                }
            }
        }
    }

    // This is a home-grown implementation which we have not had time
    // to research - it may perform poorly in some circumstances. It
    // requires twice the space of an in-place algorithm and makes
    // NlogN assigments shuttling the values between the two
    // arrays. The number of compares appears to vary between N-1 and
    // NlogN depending on the initial order but the main reason for
    // using it here is that, unlike qsort, it is stable.
    public void shuttlesort(int from[], int to[], int low, int high) {
        if (high - low < 2) {
            return;
        }
        final int middle = (low + high)/2;
        shuttlesort(to, from, low, middle);
        shuttlesort(to, from, middle, high);

        int p = low;
        int q = middle;

        /* This is an optional short-cut; at each recursive call,
        check to see if the elements in this subset are already
        ordered.  If so, no further comparisons are needed; the
        sub-array can just be copied.  The array must be copied rather
        than assigned otherwise sister calls in the recursion might
        get out of sinc.  When the number of elements is three they
        are partitioned so that the first set, [low, mid), has one
        element and and the second, [mid, high), has two. We skip the
        optimisation when the number of elements is three or less as
        the first compare in the normal merge will produce the same
        sequence of steps. This optimisation seems to be worthwhile
        for partially ordered lists but some analysis is needed to
        find out how the performance drops to Nlog(N) as the initial
        order diminishes - it may drop very quickly.  */

        if (high - low >= 4 && compare(from[middle-1], from[middle]) <= 0) {
            for (int i = low; i < high; i++) {
                to[i] = from[i];
            }
            return;
        }

        // A normal merge.

        for (int i = low; i < high; i++) {
            if (q >= high || (p < middle && compare(from[p], from[q]) <= 0)) {
                to[i] = from[p++];
            }
            else {
                to[i] = from[q++];
            }
        }
    }

    public void swap(int i, int j) {
        final int tmp = indexes[i];
        indexes[i] = indexes[j];
        indexes[j] = tmp;
    }

    // The mapping only affects the contents of the data rows.
    // Pass all requests to these rows through the mapping array: "indexes".

    @Override
    public Object getValueAt(int aRow, int aColumn) {
        checkModel();
        return model.getValueAt(indexes[aRow], aColumn);
    }

    @Override
    public void setValueAt(Object aValue, int aRow, int aColumn) {
        checkModel();
        model.setValueAt(aValue, indexes[aRow], aColumn);
    }

    public void sortByColumn(int column) {
        sortByColumn(column, true);
    }

    public void sortByColumn(int column, boolean ascending) {
        this.ascending = ascending;
        sortingColumns.removeAllElements();
        sortingColumns.addElement(new Integer(column));
        sort(this);
        super.tableChanged(new TableModelEvent(this));
    }

    // There is no-where else to put this.
    // Add a mouse listener to the Table to trigger a table sort
    // when a column heading is clicked in the JTable.
    public void addMouseListenerToHeaderInTable(JTable table) {
        final TableSorter sorter = this;
        final JTable tableView = table;
        tableView.setColumnSelectionAllowed(false);
        final MouseAdapter listMouseListener = new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                final TableColumnModel columnModel = tableView.getColumnModel();
                final int viewColumn = columnModel.getColumnIndexAtX(e.getX());
                final int column = tableView.convertColumnIndexToModel(viewColumn);
                if (e.getClickCount() == 1 && column != -1) {
                    //System.out.println("Sorting ...");
                    final int shiftPressed = e.getModifiers()&InputEvent.SHIFT_MASK;
                    final boolean ascending = (shiftPressed == 0);
                    sorter.sortByColumn(column, ascending);
                }
            }
        };
        final JTableHeader th = tableView.getTableHeader();
        th.addMouseListener(listMouseListener);
    }
}

